Modern motor vehicles are often equipped with a battery management system that facilitates the monitoring of battery current and/or of the battery voltage. In combination with such systems, a connection unit sometimes employed that includes one or more sensors to measure battery current and/or battery voltage and to provide for electrical connection to the negative pole of a motor vehicle battery.
Safety regulations relating to modern motor vehicles may also require that at least the starter, and optionally also the generator of the motor vehicle, be electrically isolated, through automatic means, from the motor vehicle battery in the event of an accident. To meet these requirements, one known connection unit has an interruption unit that interrupts the electrical connection between the motor vehicle battery and the starter and/or the generator on an activation caused by an accident. This known connection unit is provided for a connection to the positive pole of the motor vehicle battery.